(c) In the event of findings by the commissioner that there is an existing or imminent shortage of any ingredient required by section two or three of this article, and that because of such shortage the sale and distribution of flour or white bread or rolls may be impeded by the enforcement of this article, the commissioner shall issue an order, to be effective immediately upon issuance, permitting the omission of such ingredient from flour or white bread or rolls and, if he finds it necessary or appropriate, excepting such foods from labeling requirements until the further order of the commissioner. Any such findings may be made without hearing, on the basis of an order or of factual information supplied by the appropriate federal agency or officer. In the absence of any such order of the appropriate federal agency or factual information supplied by it, the commissioner on his motion may, and upon receiving the sworn statement of ten or more persons subject to this article that they believe such a shortage exists or is imminent shall, within twenty days thereafter hold a public hearing with respect thereto at which any interested person may present evidence, and shall make findings based upon the evidence presented. Whenever the commissioner has reason to believe that such shortage no longer exists, he shall hold a public hearing, at which any interested person may present evidence, and he shall make findings based upon the evidence so presented. If his findings be that such shortage no longer exists, he shall issue an order to become effective not less than thirty days after date of issuance, revoking such previous order: Provided, That undisposed floor stocks of flour on hand at the effective date of such revocation order, or flour manufactured prior to such effective date, for sale in this state may thereafter be lawfully sold or disposed of.